Hose clamps are well known coupling devices that can be found on most machinery where a flexible hose is secured to a fixture. Such hoses may convey materials such as air, water, or oil from one part of the machine to another, often under high pressure. As a result, a clamp is usually required over this interface in order to constrict the hose around the fixture and prevent it from slipping off.
A variety of prior art hose clamps exist, typically utilizing a threaded bolt or screw for use in constricting a band placed around the hose. The constricting band encompasses a portion of the hose and the bolt or screw is used to engage the corresponding threads of a worm drive on the encircled band strap, an attached nut, or a gearing system. As the threaded bolt or screw is turned, the strap is pulled forward to constrict the band. Examples of such clamping devices are disclosed in U.S. Pat. Nos. 2,750,645; 2,944,314; 4,286,361; 4,513,801; 4,638,531; 4,667,375; 4,686,747; 5,323,515; and 5,327,618. In each case, an external tool is required to turn the bolt or screw.
U.S. Pat. No. 4,480,359 discloses a circular clamp with a spring loaded lever for causing constriction of the clamp, with adjustment notches for positioning of the lever.
U.S. Pat. No. 4,083,588 discloses a cylindrical clamp with two threaded bolts extending through yokes mounted on one side of the clamp. The T-handled bolts interface with nuts positioned below the yokes on the opposite side of the clamp.
U.S. Pat. No. 2,283,179 discloses a circular clamping device with a threaded bolt attached to one side of the clamp and corresponding threaded wrench on the other side. A bar slidably fits inside an opening in the threaded wrench to allow it to be turned and tightened.
The majority of these devices tighten the clamp by employing the threads of a bolt or screw to advance a free moving opposite end of the clamp. Even with a built-in handle for turning the threaded bolt, this configuration is subject to failure of the threads when placed under high stress loading which is often required of such clamps. As such, the threads on the bolt might become stripped as well as the threads on the receiving nut.
Additionally, on a worm drive where indentations in the band engage the threaded bolt, the bolt tends to lift upwards and away from the engaged band as the tension and curvature of the constricting band increases. This can lead to slippage of the tightening mechanism whereby the band may not be constricted sufficiently to guarantee a seal around the hose. Yet another problem includes localized crimping of the clamp around the screw mechanism. As a result, an even constriction will not be applied around the circumference of the band. This may lead to damage or ineffective sealing of the clamped fixture.
Hence, what is needed in the field is a circular clamping device which eliminates the threaded engagement of a bolt with a receiving nut or worm drive on the band. Instead the clamping device should use a relatively flexible band which is advanced forward via a spiked roller which pinches down upon the band. To engage the spikes on the roller, the band should be constructed of a durable fiber woven into a fabric-like material. Such material might include woven KEVLAR, with the body of the mechanism correspondingly constructed of molded KEVLAR. Such non-metal construction will make the device impervious to corrosion. The roller would be turned via a mechanism which would eliminate the need for external tools in order to operate the clamp. This turning mechanism could come in many forms including a ratcheted or geared system for advancing the roller via a pivoting wrench, lever, or key.